Devices such as mobile cellular telephones usually have at least one antenna element by which they can communicate with other devices. If the context of the device changes, the impedance of the antenna element at a desired frequency band may also change. For example, if a user handles the device, the antenna element may electromagnetically couple with the user and the impedance of the antenna element at the desired frequency band may change as a consequence. Consequently, such a device may not be able to communicate efficiently (and may not be able to communicate at all) when the device changes context.
Furthermore, if the antenna element is operable in a first resonant frequency band and a second resonant frequency band, it may be difficult to compensate for the change in impedance of the antenna element so that the antenna element performs efficiently at both the first resonant frequency band and the second resonant frequency band.
Therefore, it would be desirable to provide an alternative device.